Teoría de la mente en los trastornos alimentarios: ¿endofenotipo de la enfermedad? / [Theory of Mind in eating disorders: endophenotype of the disease?].

UNLABELLED: Considering the clinical and empirical evidence of socio-cognitive difficulties in patients with eating disorders, this paper aims to critically review the current state of research on theory of mind in anorexia and bulimia, to evaluate if there is any alteration of it in these pathologies and to determine whether there are indicators that can be considered endophenotype. METHOD: We conducted a literature search of PubMed database, using keywords related to the topic. The papers were analyzed according to inclusion/ exclusion criteria. RESULTS: We identified seven studies of patients with anorexia, one on bulimia and four on both pathologies. Most studies reported that patients with anorexia have alterations in the theory of mind. Studies on bulimia are scarce, and their results contradictory. CONCLUSION: Research on theory of mind in eating disorders at initial level, being the most of works on anorexia. There are indicators of deficits for this pathology on ToM tasks, and they might be considered endophenotypes, although studies that evaluate unaffected first-degree relatives are still lacking.

Perspectiva evolucionista de los trastornos de la conducta alimentaria / Evolutionary perspective of eating disorders

Background: Evolutionary theory has contributed with physiological, psychological and behavioral explanations to the comprehension and treatment of eating disorders (ED). The aim of this review is to analyze the relationship between ED and the attachment theory and natural selection based hypotheses (famine flight, reproductive suppression and intrasexual competition). Insecure attachment is characteristic of ED and significantly interferes in the individuation developmental process. Maternal attachment is usually ambivalent; mainly avoidant in anorexics and anxious in bulimics. Anorexic syndrome evokes ancestral adaptive mechanisms to face food scarcity, status achievement and threat of group exclusion. Suppression of reproductive capacity in anorexics, favored by family dynamics, represents a self-sacrifice to obtain the benefit of its members through genetic altruism. Feminine intrasexual competence is related to nubile features in order to attract and retain high quality and long-term partners. Therefore, from an evolutionary perspective, ED symptomatology may be described as a self-destructive adaptive state of lack of control, in response to a particular genetic phenotype plasticity, environmental factors and cognitive processes.

Asociación de polimorfismos de los genes CRF-BP, SLC6A4 y restricción alimentaria crónica: un estudio preliminar / CRF-BP and SLC6A4 gene polymorphisms among restrained eaters

Background: Restrained eaters (RE) are a group of individuals who constantly restrict their eating. However, they usually alternate restriction with periods of overeating. Aim: To evaluate the possible association of CRF-BP and SLC6A4 gene polymorphisms with chronic alimentary restriction. Material and Methods: The Spanish version of the Revised Restraint Scale was applied to 132 women aged 18 to 25 years. They were divided in a group classified as restrained eaters (RE) and a group of unrestrained eaters. The 5-HTTLPR and CRF-BPs11 polymorphisms of the SLC6A4 and CRF-BP genes were evaluated by polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (RFLP), respectively. Results: There was a significant association between the s/s homozygous genotype for the 5-HTTLPR polymorphism of SLC6A4 gene and RE condition (p = 0.033). However, this association was not observed for the CRF-BPs11 polymorphism. Conclusions: The presence of s/s genotype is associated with the RE condition, being the presence of a s allele, a risk factor for this condition.

Genetics in eating disorders: extending the boundaries of research / Genética em transtornos alimentares: ampliando os horizontes de pesquisa

OBJECTIVE: To review the recent literature relevant to genetic research in eating disorders and to discuss unique issues which are crucial for the development of a genetic research project in eating disorders in Brazil. METHOD: A computer literature review was conducted in the Medline database between 1984 and may 2005 with the search terms "eating disorders", "anorexia nervosa", "bulimia nervosa", "binge eating disorder", "family", "twin" and "molecular genetic" studies. RESULTS: Current research findings suggest a substantial influence of genetic factors on the liability to anorexia nervosa and bulimia nervosa. Genetic research with admixed populations should take into consideration sample size, density of genotyping and population stratification. Through admixture mapping it is possible to study the genetic structure of admixed human populations to localize genes that underlie ethnic variation in diseases or traits of interest. CONCLUSIONS: The development of a major collaborative genetics initiative of eating disorders in Brazil and South America would represent a realistic possibility of studying the genetics of eating disorders in the context of inter ethnic groups, and also integrate a new perspective on the biological etiology of eating disorders.

OBJETIVO: Revisar a literatura atual concernente à pesquisa genética em transtornos do comportamento alimentar e discutir questões relevantes ao desenvolvimento de um projeto de pesquisa genética nessa área no Brasil. MÉTODO: A revisão realizada utilizou a base de dados Medline, no período de 1984 a maio de 2005, com os seguintes termos de busca: "anorexia nervosa", "bulimia nervosa", "eating disorders", "binge eating disorder", "family studies", "twin studies", "molecular genetics studies". RESULTADOS: Os dados atuais apontam para uma contribuição relevante dos fatores genéticos na suscetibilidade à anorexia e à bulimia nervosa. A pesquisa genética com populações miscigenadas deve levar em consideração o tamanho da amostra, a densidade de genotipagem e a estratificação populacional. Através de "admixture mapping" é possível estimar a estrutura genética destas populações e localizar genes relacionados à variação étnica de doenças ou traços de interesse. CONCLUSÕES: O desenvolvimento de uma grande iniciativa de colaboração em genética de transtornos alimentares no Brasil e na América Latina viabilizará estudar os fatores genéticos em transtornos do comportamento alimentar no contexto de grupos inter-étnicos, e integrar uma nova perspectiva biológica à etiologia destes distúrbios.